Quick return straight line pump jack



Dec. 20, 1932.

MCCROSKY QUICK RETURN STRAIGHT LINE PUMP JACK Filed Dec. 18, 1931 i .1/r Iig 4a se /6 4/ ||l j! 1 "A l I r||||||| l .I

27 m JHM HIHHIIII 'IHII 1 nl/HM Patented Dec. 20, 1932 BET VAIIABLE copyUNITED STATES FREI) B. MCCROSKY, F WALNUT PARK, CALIFORNIA QUICK RETURNSTRAIGHT LINE PUMP JACK .Application led December 18, 1931. Serial No.581,826.

My invention relates to improvements in l pump jacks.

An important object of my invention is to provide an improved pump jack,the paramount feature of which includes a straight line pumping strokeand a quick return motion of the pumping parts at the end of the stroke.

In addition to the foregoing object I desire 19 to point out othersalient features which are incorporated in my invention which are newand novel, and are well adapted for use in the oil pumping industry.These features include a trapeze sling for the polish rod, whicheliminates the heavy mule-head, thus providing for less wear on cables,greater freedom of polish rod, greater ease to swing cables in and outof play, together with means to adjust the walking beam to permit ofample space whereby to withdraw the rods from the well.

Another novel feature is the provision of improved supporting, balancingand counterbalancing means of the walking beam and its cooperatingparts.

Still other objects, advantages and features of invention willhereinafter appear.

In the drawing accompanying I have o shown what constitutes, in general,a pre- 9 ferred embodimentof my inventiomwhich may, however, be used instill other branches of mechanics than that in connection with whichitis disclosed, and I do not wish to be o: lilnited to the formsembodied, since permissible changes may he resorted to without departingfrom the scope of the invention as hereinafter claimed, and such changesand modifications are included within its scope.

IVith'reference to the drawing:

Fig. 1 is a perspective. view of a pumping unit containing an embodimentof my invention.

Figs. 2 and 3 are diagrams which display relative relation of parts nearthe beginning and ending of the pumping stroke whereby to depict thequick return action ofthe pump.

Figs. 4 and 5 show a modification and also display respectively therelative postions of q the walking beam counter-weight at the limitedswing of the pitman.

`2 is a double reduction' speed reducer pump- Fig. 6 is a section takenon the line 6 6 of In the drawing the derrick 1 is supported by aderrick Hoor 2. Mounted on said floor serves as the band-wheel shaft andto it is 65 keyed the crank 7. The pumping unit 3 is a self containedpumping unit having all gears enclosed and running in a bath of oil. Thecrank has four different lengths of stroke which permits the operator toadjust the capacity of the machine to that of the well without changingthe number of strokes per minute, and there is further provided meansfor finer adjustment as will hereinafter be pointed out. IYhis featureis particularly desirable When there is a direct connection of the motorand machine.

Beyond the wrist pin holes of the crank is secured a weight 8, saidweight being adapted for cooperation with a like balance 9 incombinatiodwith the walking beam 10 or with the weight 9a of Figs. l and5.

To the crank 7 is fastened one end of the pitman 11 by means of a wristpin 12. the other end of said pit-man being fastened to a .pin 13pivotally swung in a link 14 oscillative with respect to a shaft 15journaled in bearings 16 fastened to the derrick frame 1. The link 11 isprovided with a plurality of holes 17, which taken in conjunction withthe holes 18 in the crankgprovide for minute adjustment for regulatingthe pumping stroke.

Centrally of the ptman is a boxed-in aperture 19 ,through which thewalking beam 20 projects and within which is mounted the roller bearingwheel 21 by means of the pin 22. The walking beam 2O is liltinglymounted upon a shaft Q?, at substantially its midlength. Said shaft isjournalled in pillow blocks S24 which are supported by the derrick shownconveniently near their limiting position. V

4The walking beam 20 is provided with a recessed face y26 that forms atrack upon which the wheel 21 plays on the pumping and return strokesaid track being substantially in line with the axis upon which thewalking beam is tiltingly mounted. Theapproximate beginning and endingof the stroke is diagrammatically shown in Figs. 2 and 3. The depressedcharacter of the track 26 safeguards the walking beam against edge-wisedisplacement at its working strain required. From Figs. 4, 5 and 6 itwill be seen how I vary the effect of the weight on the quick returnstroke while the pumping /rods' are being lowered.

Referring to the modification .shown in Figs. 4 and 5 and 6, on the beam10 I fasten racksV 28 and movable on said racks are the f, pinions 29mounted on the shaft 31 journalled in the boxed-in aperture 19, therebeing a bearing roller 30 interposed between the two pinions yetintegral therewith, said roller resting upon the walking beam trackrail- I26a secured to the upper side of the walking beam'.

The head of the beam 20 is fastened byY a pin 27 to a link 37, and saidlink is pivotally swung from a pin 38 in a fulcrum link 29 ,oscillativeupon the shaft 40 journalled in bearings 41 fastened to the derrickframe.

The distance between the pivot pins of the link 39 is the same as thedistance between pin 27 and axis of the shaft 23, and the suspension lbar 42 to which the trapeze cables 43 are fastened, is placed at themid-length of the link 37. Hence the polish rod 44, fastenedat themid-length of the spreader bar 45, will be elevated and lowered in astraight line as the A `crank 7 rotates to reciprocate the wheel 21 'onthe surface of the beam 20. The same equalization will result with'themodification shown in Figs. 4 and 5.

A turnbuckle (not shown) could be provided on one of the cable lines 43to assure the operator of equal tension on other lines while pumping.

Referring to the modification shown in Figs. 4 to 6, the walking beam10, pivotally supported at 10a, is provided with a double rack 28 whichforms -a track whereon the double cog wheel 29 travels. Said track has acentral tread portion 26a upon which bears a roller portion 30 which islocated between and preferably formed integral with the two edges of thecog wheel 29.

25 which support pivot under the heavy' Said double cog wheel 29 ishoused within a box or yoke 19a with which the pitman 11a is provided ata point intermediate its .pivotal mountings which are not shown in Figs.4 and 5, but which it is to be understood are the same as illustrated inFig. 1. The walking and weight 9a causes the position of said v weightto be automatically adjusted during the operation of the walking beam insuch a manner as to vary the counter-balancing effect of said weight sothat it will produce the `desired counter-balancing effect during allpositions of the walking beam. 4

In Fig. 2 is diagrammatically shown the position of the parts at thebeginning of the pumping stroke. The counter-balancing weights are notshown in this view, but it will be readily seen that as the crank 7proceeds to move in' the clock-wise direction its weight 8 (Fig.` 1)will most effectively aid the pumping stroke produced while at the sametime the weight 9 (Fig. 1) will, providing the modification shown inFigs. 4 and 5 be used, be in the extended position where it willeffectively supplement the power required for the pumping stroke. InFig. 3 the parts are in the position they assume at the beginning of thedown stroke where power is not required but additional speed is desired.In this position of the parts the weight 9a will be retracted to theposition shown in Fig. 5 where it will exert minimum opposition to theupward movement of the outer end of the walking beam 10.

I claim:

1. In a quick return stroke construction for pumps, a driving shaft, acrank fixed to said shaft, a pitman having one of its ends operativelyconnected with said crank to be reciprocated thereby, a link adjustablyand pivotally connected with the other end of said pitman, a supportwhereon saidlink is pivotally mounted, a polish rod, a walking beampivotally supported between its ends, its inner end being connected withsaid polish rod, and having its outer end portion extending transverselyand loosely through said pitman, said pitman having a shiftingengagement with the outer portion of said walking beam to regulate theupstroke of the pump, said shifting engagement being nearest to thepivotal support of said walking beam during the down stroke of the pumpto permitan accelerated down stroke, and means adapted to operativelyconnect the inner end of said walking beam with said polish rod.

Q. In a quick return stroke construction for pumps. a driving shaft. acrank fixed to said shaft. a pitman having one of its ends operativellvconnected with said crank to be reciprocated thereb'v. a link adjustablvand pivotallv connected with the other end of said pitman. a supportwhereon said link is pivotall v mounted. a polish rod. a walking beampivotalltv supported between its ends. its inner end being connectedwith said polish rod. and having its outer end portion extendingtransversely and loosely through said pitman. said pitman having ashifting engagement with the outer portion of said walking beam toregulate th'e upstroke of the pump. said shifting engagement beingnearest to the pivotal support of said walking beam during the downstroke of the pump to permit an accelerated down stroke. and meansadapted to operativel)v connect the inner end of said walking beam withsaid polish rod. said walking beam having a depressed track along itsupper side. said pitman having anti-friction means adapted to travelalong said track.

3. In a quick return stroke construction for pumps. a Walking beamhaving an upwardlwv directed face with a recessed portion. said recessedportion forming a track. a pitman to operate said walking beam. and ananti-friction roller carried b v said pitman and positioned to engagesaid track to depress the portion of said walking beam whereon saidtrack is formed.

4. In a quick return stroke construction for pumps. in combination. awalking beam. an upright pitman having a transverse aperture extendingthrough it between its ends. and an anti-friction roller mounted uponsaid pitman within said aperture and positioned to engage. travel alongand depress a portion of said walking beam which extends through saidaperture.

5. In a quick return stroke construction for pumps. in combination. aWalking beam provided with an upwardlyv facing rack which extendstherealong. a pitman. a pivotal connection for one end of said pitman, acrank arm to which the other end of said pitman is pivotall)v connected.a cog wheel carried bv said pitman intermediate its ends. said wheelbeing constructed and arranged to engage and travel along said rack tooperate said walking beam during the upstroke of the pump. a weightmounted upon said walking beam and movable lengthwise thereof. and

means eccentrieallv connecting said wheel with said weight to adjust theposition of said weight in order to var)7 automaticallv thecounter-balancing effect of said weight dure ing the operation of saidwalking beam.

6. In a quick return stroke construction for pumps. in combination. awalking beam provided with an upwardly facing double rack which extendstherealong, a pitman, a pivotal connection for one end of said pitman, acrank arm to which the other end of said pitman is pivotally connected,a double cog wheel carried b v said pitman intermediate its ends totravel along said double rack, said walking beam having a tread portionbetween the two parts of said rack and said cog wheel having a centralroller portion to engage said tread portion to bear upon said walkingbeam during the up-stroke of the pump. and means eccentricallyconnecting said wheel with said weight to change the position thereof tovary automatically its counter-balancing effect.

i'. In a quick return stroke construction' for pumps. in combination. awalking beam provided with an upwardly facing rack which extendstherealong', a pitman. a pivotal connection for one end of said pitman,a crank arm kto which the other end of said pitman is pivotallvconnected, a cog wheel carried b'v said pitman intermediate its ends,said wheel being constructed and arranged to engage and travel alongsaid rack to operate said walking beam during the up-st-roke of thepump. a weight mounted upon said walking beam and movable lengthwisethereof. a crank carried bv said wheel. and a connecting-.rod connectingsaid crank with said weight in order to vary automatically thecounter-balancing effect of said weightduring the operation of saidwalking beam.

8. In a device of the character described,

a frame. a walking beam pivotallyv supported thereon. a fulcrum linkhaving one end pivotall v fastened to said frame, a pendant link havingits upper end pivotedto the free end of said fulcrum link. the lower endof said pendant link being pivoted to said walking beam. a polish rod.and means connected with said pendant link at substantially itsmidlcngth whereby said polish rod is suspended therefrom.

9. In a device of the character described, a frame. a walking beampivotally supported thereon. a fulcrum link having one end pivotall vfastened to said frame. a pendant link having its upper end pivoted. tothe free end of said fulcrum link. the lower end of said pendant linkbeing pivoted -to said walking beam, a polish rod, and a trapezeconnected with said pendant link at substantially its mid-lengthwhereb)Y said polish rod is suspended therefrom.

FRED B. 'MCCROSKY-

